In residential districts it is now common practice to provide for the laying of underground cables and irrigation pipe systems. Underground irrigation systems are now also commonly in use for golf courses and the like. If the backfill earth dug from the trench is not compacted sufficiently, there will remain a mound of soil and the tendency of the soil to later settle and form a depression along the line of the underground installation. This results in detracting from the appearance of the lawn or golf course, along with the necessity of incurring additional expense in filling the depression and then sodding or seeding the same.
To overcome this objection in the filling of the narrow trench required for the underground installations, a usual backhoe machine has been provided with a compaction wheel attachment dependent upon the weight of the backhoe for compacting, and the fore and aft movement of the backhoe as a self-propelled mobile frame. The compacting attachment thus requires an expensive machine for its operation and sufficient clearance around the formed trench to allow manipulation of the backhoe.
A further practice has been the utilization of a relatively small portable tamping machine which requires two operators. One operator is necessary to balance and guide the machine in the trench, while the second operator manually pulls the machine through the trench by means of a rope or like connection. These machines are generally ,of a light weight and, even though vibratory in operation, they are difficult and inconvenient to handle, along with requiring substantial maintenance expense and skill in handling.
A further procedure is shown in Pat. No. 3,680,452 herein a compacting roller is centrally supported on the bucket or scoop of a loader machine. In use, the machine straddles the ditch and is piloted back and forth along the ditch to roll and compact the ditch floor. For compaction purposes, the entire front end weight of the loader may be carried by the compacting roller by operating the hydraulic down pressure of the loader so as to transmit the loader weight to the roller. Additional weight may be carried by the roller by partially loading the loader bucket with dirt or rock material. The loader bucket may also carry a pulsating unit to facilitate compaction. The roller at the front end of the loader machine and the manipulation of the loader weight on the roller makes for steering difficulties in following the trench line. Additionally, the weight of the loader machine may result in a collapse of the trench sidewalls or in disfigurement of the ground surface adjacent the trench sidewalls.